Watcher for PlantUML on MacOS

README.md

Install

brew install plantuml fswatch
# Download plantuml-watch.sh
chmod +x ./plantuml-watch.sh
mkdir -p /usr/local/bin
mv ./plantuml-watch.sh /usr/local/bin/plantuml-watch
# Confirm /usr/local/bin is in PATH or mv script to directory in PATH
echo $PATH

Usage

Use plantuml-watch exactly as you would plantuml. Assuming the file foobar.puml is in the current directory, you should see the output below and the default app for the output filetype should open automatically and refresh after every saved change to the the source file.

$ plantuml-watch ./foobar.puml 
Watching ./foobar.puml for changes...

plantuml-watch.sh

#!/bin/bash

# Check if at least one argument is provided
if [ $# -lt 1 ]; then
    echo "Usage: $0 <file.puml> [additional arguments for plantuml]"
    exit 1
fi

# Get the file to watch and any additional arguments for plantuml
WATCH_FILE="$1"
shift
PLANTUML_ARGS="$@"

# Extract the base name and directory of the WATCH_FILE
BASE_NAME=$(basename "$WATCH_FILE" .puml)
DIR_NAME=$(dirname "$WATCH_FILE")

# Determine the output format and file extension
OUTPUT_FORMAT="png"  # Default output format
EXTENSION="png"      # Default extension

# Check for output format in the arguments
for arg in "$@"; do
    if [[ "$arg" == "-t"* ]]; then
        OUTPUT_FORMAT="${arg#-t}"
        EXTENSION="${OUTPUT_FORMAT}"
        break
    fi
done

# Handle cases where the extension might be special (e.g., "-txmi")
if [[ "$EXTENSION" == "xmi" || "$EXTENSION" == "dot" || "$EXTENSION" == "txt" || "$EXTENSION" == "pdf" ]]; then
    EXTENSION="${OUTPUT_FORMAT}"
elif [[ "$EXTENSION" == "svg" ]]; then
    EXTENSION="svg"
elif [[ "$EXTENSION" == "eps" ]]; then
    EXTENSION="eps"
else
    EXTENSION="png"  # Default to PNG for unknown types
fi

# Determine the output file path
OUTPUT_FILE="${DIR_NAME}/${BASE_NAME}.${EXTENSION}"

echo "Watching $WATCH_FILE for changes..."

# Initial run of plantuml
plantuml "$WATCH_FILE" $PLANTUML_ARGS

# Open the initial output file
if [ -f "$OUTPUT_FILE" ]; then
    open "$OUTPUT_FILE"
fi

# Use fswatch to watch for changes and re-run plantuml
fswatch -o "$WATCH_FILE" | while read f; do
    echo "File $WATCH_FILE changed, re-running plantuml..."
    plantuml "$WATCH_FILE" $PLANTUML_ARGS
    if [ -f "$OUTPUT_FILE" ]; then
        open "$OUTPUT_FILE"
    else
        echo "Output file not found: $OUTPUT_FILE"
    fi
done